1. Field of the Invention
This invention generally relates to semiconductor devices and integrated circuits that require electrostatic discharge (hereinafter referred to as "ESD") protection. In typical electrical circuits, such devices include Resistor-Capacitor (hereinafter referred to as "RC") or Resistor-Capacitor-Inductor (hereinafter referred to as "RCL") networks and fabrication methods therefor. Specifically, this invention relates to an improved semiconductor device and a method for manufacturing such an improved semiconductor device which provides protection against ESD for active or passive devices or any type of integrated circuit.
2. Description of the Related Art
In the past art, the primary method for integrating protection of ESD in RC Network types of semiconductor devices was to use or incorporate certain types of diodes, i.e. Schottky diodes and Zener diodes to provide for ESD protection. For example, Rao et al. (U.S. Pat. Nos. 5,355,014 and 5,770,886) employs a Schottky diode for ESD protection.
However, one primary disadvantage of the use of a Schottky/Zener diode technique for ESD protection is the added complexity of the process flow for manufacturing these fairly complicated semiconductor devices. The prior art semiconductor process for fabricating these types of semiconductor devices usually required an epitaxy growth process step to obtain or form regions of P type conductivity, formation of the LOCOS field isolation and formation of a multi-layer metalization system on the backside of the semiconductor wafer.
Therefore, a simpler, more cost effective and more reliable semiconductor device and semiconductor process solution was needed or required as contrasted to both the semiconductor device and process complexity incurred by the incorporation of Schottky/Zener diodes to provide ESD protection for use with, for example, RC network semiconductor devices.